首先声明，这些内容都是借鉴来的，稍微改动了一下。

主要就是三个应用类ColumnGroup， GroupableTableHeader，GroupableTableHeaderU
和一个示例类GroupableHeaderExample

1、ColumnGroup类主要负责多表头的构建

import java.awt.Component;
import java.awt.Dimension;
import java.util.Enumeration;
import java.util.Vector;

import javax.swing.JLabel;
import javax.swing.JTable;
import javax.swing.UIManager;
import javax.swing.table.DefaultTableCellRenderer;
import javax.swing.table.JTableHeader;
import javax.swing.table.TableCellRenderer;
import javax.swing.table.TableColumn;

public class ColumnGroup {
    protected TableCellRenderer renderer;

    protected Vector v;

    protected String text;

    protected int margin = 0;

    public ColumnGroup(String text) {
        this(null, text);
    }

    public ColumnGroup(TableCellRenderer renderer, String text) {
        if (renderer == null) {
            this.renderer = new DefaultTableCellRenderer() {
                public Component getTableCellRendererComponent(JTable table,
                        Object value, boolean isSelected, boolean hasFocus,
                        int row, int column) {
                    JTableHeader header = table.getTableHeader();
                    if (header != null) {
                        setForeground(header.getForeground());
                        setBackground(header.getBackground());
                        setFont(header.getFont());
                    }
                    setHorizontalAlignment(JLabel.CENTER);
                    this.setText((value == null) ? "" : value.toString());
                    setBorder(UIManager.getBorder("TableHeader.cellBorder"));
                    return this;
                }
            };
        } else {
            this.renderer = renderer;
        }
        this.text = text;
        v = new Vector();
    }

    /**
     * @param obj
     *            TableColumn or ColumnGroup
     */
    public void add(Object obj) {
        if (obj == null) {
            return;
        }
        v.addElement(obj);
    }

    /**
     * @param c
     *            TableColumn
     * @param v
     *            ColumnGroups
     */
    public Vector getColumnGroups(TableColumn c, Vector g) {
        g.addElement(this);
        if (v.contains(c))
            return g;
        Enumeration enumeration = v.elements();
        while (enumeration.hasMoreElements()) {
            Object obj = enumeration.nextElement();
            if (obj instanceof ColumnGroup) {
                Vector groups = (Vector) ((ColumnGroup) obj).getColumnGroups(c,
                        (Vector) g.clone());
                if (groups != null)
                    return groups;
            }
        }
        return null;
    }

    public TableCellRenderer getHeaderRenderer() {
        return renderer;
    }

    public Object getHeaderValue() {
        return text;
    }

    public int getSize() {
        return v == null ? 0 : v.size();
    }

    public Dimension getSize(JTable table) {
        Component comp = renderer.getTableCellRendererComponent(table,
                getHeaderValue(), false, false, -1, -1);
        int height = comp.getPreferredSize().height;
        int width = 0;
        Enumeration enumeration = v.elements();
        while (enumeration.hasMoreElements()) {
            Object obj = enumeration.nextElement();
            if (obj instanceof TableColumn) {
                TableColumn aColumn = (TableColumn) obj;
                width += aColumn.getWidth();
                width += margin;
            } else {
                width += ((ColumnGroup) obj).getSize(table).width;
            }
        }
        return new Dimension(width, height);
    }

    /**
     *
     * 创建日期:(2003-7-14 10:53:26)
     *
     * @return java.lang.String
     */
    public java.lang.String getText() {
        return text;
    }

    /**
     * 列表头中删除Column 创建日期:(2002-9-25 15:49:00)
     */
    public boolean removeColumn(ColumnGroup ptg, TableColumn tc) {
        boolean retFlag = false;
        if (tc != null) {
            for (int i = 0; i < ptg.v.size(); i++) {
                Object tmpObj = ptg.v.get(i);
                if (tmpObj instanceof ColumnGroup) {
                    retFlag = removeColumn((ColumnGroup) tmpObj, tc);
                    // 如果找到返回
                    if (retFlag)
                        break;
                } else if (tmpObj instanceof TableColumn) {
                    // 判断是否查找的对象
                    if (tmpObj == tc) {
                        ptg.v.remove(i);
                        retFlag = true;
                        break;
                    }
                }
            }
        }
        return retFlag;
    }

    /**
     * 列表头中删除ColumnGrp 删除返回true,否则返回false; 创建日期:(2002-9-25 15:49:00)
     */
    public boolean removeColumnGrp(ColumnGroup ptg, ColumnGroup tg) {
        boolean retFlag = false;
        if (tg != null) {
            for (int i = 0; i < ptg.v.size(); i++) {
                Object tmpObj = ptg.v.get(i);
                if (tmpObj instanceof ColumnGroup) {
                    // 判断是否查找的对象
                    if (tmpObj == tg) {
                        ptg.v.remove(i);
                        retFlag = true;
                        break;
                    } else {
                        retFlag = removeColumnGrp((ColumnGroup) tmpObj, tg);
                        // 如果找到返回
                        if (retFlag)
                            break;

                    }
                } else if (tmpObj instanceof TableColumn) {
                    break;
                }
            }
        }
        return retFlag;
    }

    public void setColumnMargin(int margin) {
        this.margin = margin;
        Enumeration enumeration = v.elements();
        while (enumeration.hasMoreElements()) {
            Object obj = enumeration.nextElement();
            if (obj instanceof ColumnGroup) {
                ((ColumnGroup) obj).setColumnMargin(margin);
            }
        }
    }

    public void setHeaderRenderer(TableCellRenderer renderer) {
        if (renderer != null) {
            this.renderer = renderer;
        }
    }

    /**
     *
     * 创建日期:(2003-7-14 10:53:26)
     *
     * @param newText
     *            java.lang.String
     */
    public void setText(java.lang.String newText) {
        text = newText;
    }
}

2、GroupableHeader继承自JTableHeader，为多表头结构的管理者

import java.util.Enumeration;
import java.util.Vector;

import javax.swing.table.JTableHeader;
import javax.swing.table.TableColumn;
import javax.swing.table.TableColumnModel;

/**
 * GroupableTableHeader
 * @author flyx
 */

public class GroupableTableHeader extends JTableHeader {
    private static final String uiClassID = "GroupableTableHeaderUI";
    protected Vector columnGroups = null;
  public GroupableTableHeader(TableColumnModel model) {
    super(model);
    setUI(new GroupableTableHeaderUI());
    setReorderingAllowed(false);
    setRequestFocusEnabled(false);
  }                                      
public void addColumnGroup(ColumnGroup g) {
    if (columnGroups == null) {
        columnGroups = new Vector();
    }
    columnGroups.addElement(g);
}
/**
 *
 * 创建日期:(2001-8-31 15:54:29)
 */
public void clearColumnGroups() {
    columnGroups = null;
}
public ColumnGroup[] getColumnGroups() {
    ColumnGroup[] retg=null;
    if (columnGroups.size()>0) {
        retg=new ColumnGroup[columnGroups.size()];
        columnGroups.copyInto(retg);
    }
    return retg;
}
public Enumeration getColumnGroups(TableColumn col) {
    if (columnGroups == null)
        return null;
    Enumeration enum = columnGroups.elements();
    while (enum.hasMoreElements()) {
        ColumnGroup cGroup = (ColumnGroup) enum.nextElement();
        Vector v_ret = (Vector) cGroup.getColumnGroups(col, new Vector());
        if (v_ret != null) {
            return v_ret.elements();
        }
    }
    return null;
}
/**
 * Identifies whether or not this component can receive the focus.
 * A disabled button, for example, would return false.
 *
 * @return true if this component can receive the focus
 */
public boolean isFocusTraversable() {
    return super.isFocusTraversable() && isRequestFocusEnabled();
}
public void setColumnMargin() {
    if (columnGroups == null)
        return;
    int columnMargin = getColumnModel().getColumnMargin();
    Enumeration enum = columnGroups.elements();
    while (enum.hasMoreElements()) {
        ColumnGroup cGroup = (ColumnGroup) enum.nextElement();
        cGroup.setColumnMargin(columnMargin);
    }
}
public void setReorderingAllowed(boolean b) {
    reorderingAllowed = b;
}
}

3、GroupableTableHeaderUI继承自BasicTableHeaderUI，是多表头的画匠

import java.awt.Component;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Rectangle;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Vector;

import javax.swing.JComponent;
import javax.swing.JLabel;
import javax.swing.JTable;
import javax.swing.UIManager;
import javax.swing.plaf.basic.BasicTableHeaderUI;
import javax.swing.table.*;

/**
 * 多表头TableHeaderUI
 *
 * @author flyx
 */
public class GroupableTableHeaderUI extends BasicTableHeaderUI {
    private int m_height;

    private Dimension createHeaderSize(long width) {
        TableColumnModel columnModel = header.getColumnModel();
        width += columnModel.getColumnMargin() * columnModel.getColumnCount();
        if (width > Integer.MAX_VALUE) {
            width = Integer.MAX_VALUE;
        }
        return new Dimension((int) width, getHeaderHeight());
    }

    /**
     * 获得该多表头下的基本列数(zjb) 递归 创建日期:(02-4-8 18:03:56)
     *
     * @return int
     * @param cg
     *            nc.ui.pub.beans.table.ColumnGroup
     */
    private int getColCountUnderColGroup(ColumnGroup cg, int iCount) {
        Vector v = cg.v;
        for (int i = 0; i < v.size(); i++) {
            Object obj = v.elementAt(i);
            if (obj instanceof ColumnGroup)
                iCount = getColCountUnderColGroup((ColumnGroup) obj, iCount);
            else
                iCount++;
        }
        return iCount;
    }

    public int getHeaderHeight() {
        int height = 0;
        TableColumnModel columnModel = header.getColumnModel();
        for (int column = 0; column < columnModel.getColumnCount(); column++) {
            TableColumn aColumn = columnModel.getColumn(column);
            TableCellRenderer renderer = aColumn.getHeaderRenderer();
            //
            if (renderer == null) {
                renderer = new DefaultTableCellRenderer() {
                    public Component getTableCellRendererComponent(
                            JTable table, Object value, boolean isSelected,
                            boolean hasFocus, int row, int column) {
                        JTableHeader header = table.getTableHeader();
                        if (header != null) {
                            setForeground(header.getForeground());
                            setBackground(header.getBackground());
                            setFont(header.getFont());
                        }
                        setHorizontalAlignment(JLabel.CENTER);
                        setText((value == null) ? "" : value.toString());
                        setBorder(UIManager.getBorder("TableHeader.cellBorder"));
                        return this;
                    }
                };
            }
            //
            Component comp = renderer.getTableCellRendererComponent(header
                    .getTable(), aColumn.getHeaderValue(), false, false, -1,
                    column);
            int cHeight = comp.getPreferredSize().height;
            Enumeration enumeration = ((GroupableTableHeader) header)
                    .getColumnGroups(aColumn);
            if (enumeration != null) {
                while (enumeration.hasMoreElements()) {
                    ColumnGroup cGroup = (ColumnGroup) enumeration
                            .nextElement();
                    cHeight += cGroup.getSize(header.getTable()).height;
                }
            }
            height = Math.max(height, cHeight);
        }
        height = Math.max(height, m_height);
        return height;
    }

    public Dimension getPreferredSize(JComponent c) {
        long width = 0;
        Enumeration enumeration = header.getColumnModel().getColumns();
        while (enumeration.hasMoreElements()) {
            TableColumn aColumn = (TableColumn) enumeration.nextElement();
            width = width + aColumn.getWidth();
        }

        return createHeaderSize(width);
    }

    public void paint(Graphics g, JComponent c) {
        Rectangle clipBounds = g.getClipBounds();
        if (header.getColumnModel() == null)
            return;
        ((GroupableTableHeader) header).setColumnMargin();
        int column = 0;
        Dimension size = header.getSize();
        Rectangle cellRect = new Rectangle(0, 0, size.width, size.height);
        Hashtable h = new Hashtable();
        int columnMargin = header.getColumnModel().getColumnMargin();
        Enumeration enumeration = header.getColumnModel().getColumns();
        while (enumeration.hasMoreElements()) {
            cellRect.height = size.height;
            cellRect.y = 0;
            TableColumn aColumn = (TableColumn) enumeration.nextElement();
            Enumeration cGroups = ((GroupableTableHeader) header)
                    .getColumnGroups(aColumn);
            if (cGroups != null) {
                int groupHeight = 0;
                while (cGroups.hasMoreElements()) {
                    ColumnGroup cGroup = (ColumnGroup) cGroups.nextElement();
                    Rectangle groupRect = (Rectangle) h.get(cGroup);
                    if (groupRect == null) {
                        groupRect = new Rectangle(cellRect);
                        Dimension d = cGroup.getSize(header.getTable());
                        if (!System.getProperty("java.vm.version").startsWith(
                                "1.2")) {
                            int iColCount = getColCountUnderColGroup(cGroup, 0); // 获得该多表头下的基本列数(zjb)
                            // System.out.println(iColCount);
                            groupRect.width = d.width - iColCount
                                    * columnMargin;
                        } else
                            groupRect.width = d.width;
                        groupRect.height = d.height;
                        h.put(cGroup, groupRect);
                    }
                    paintCell(g, groupRect, cGroup);
                    groupHeight += groupRect.height;
                    cellRect.height = size.height - groupHeight;
                    cellRect.y = groupHeight;
                }
            }
            if (!System.getProperty("java.vm.version").startsWith("1.2"))
                cellRect.width = aColumn.getWidth();
            else
                cellRect.width = aColumn.getWidth() + columnMargin;

            if (cellRect.intersects(clipBounds)) {
                paintCell(g, cellRect, column);
            }
            cellRect.x += cellRect.width;
            column++;
        }
    }

    private void paintCell(Graphics g, Rectangle cellRect, int columnIndex) {
        TableColumn aColumn = header.getColumnModel().getColumn(columnIndex);
        TableCellRenderer renderer = aColumn.getHeaderRenderer();
        //
        if (renderer == null) {
            renderer = new DefaultTableCellRenderer() {
                public Component getTableCellRendererComponent(JTable table,
                        Object value, boolean isSelected, boolean hasFocus,
                        int row, int column) {
                    JTableHeader header = table.getTableHeader();
                    if (header != null) {
                        setForeground(header.getForeground());
                        setBackground(header.getBackground());
                        setFont(header.getFont());
                    }
                    setHorizontalAlignment(JLabel.CENTER);
                    setText((value == null) ? "" : value.toString());
                    setBorder(UIManager.getBorder("TableHeader.cellBorder"));
                    return this;
                }
            };
        }
        //
        // Component component =
        // renderer.getTableCellRendererComponent(header.getTable(),
        // aColumn.getHeaderValue(), false, false, -1, columnIndex);
        //
        String headerValue = aColumn.getHeaderValue().toString();
        Component component = renderer.getTableCellRendererComponent(header
                .getTable(), headerValue, false, false, -1, columnIndex);
      
        rendererPane.add(component);
        rendererPane.paintComponent(g, component, header, cellRect.x,
                cellRect.y, cellRect.width, cellRect.height, true);
    }

    private void paintCell(Graphics g, Rectangle cellRect, ColumnGroup cGroup) {
        TableCellRenderer renderer = cGroup.getHeaderRenderer();
        //
        if (renderer == null) {
            renderer = new DefaultTableCellRenderer() {
                public Component getTableCellRendererComponent(JTable table,
                        Object value, boolean isSelected, boolean hasFocus,
                        int row, int column) {
                    JTableHeader header = table.getTableHeader();
                    if (header != null) {
                        setForeground(header.getForeground());
                        setBackground(header.getBackground());
                        setFont(header.getFont());
                    }
                    setHorizontalAlignment(JLabel.CENTER);
                    setText((value == null) ? "" : value.toString());
                    setBorder(UIManager.getBorder("TableHeader.cellBorder"));
                    return this;
                }
            };
        }
        //
        // Component component =
        // renderer.getTableCellRendererComponent(header.getTable(),
        // cGroup.getHeaderValue(), false, false, -1, -1);
        //
        String headerValue = cGroup.getHeaderValue().toString();
        Component component = renderer.getTableCellRendererComponent(header
                .getTable(), headerValue, false, false, -1, -1);

        rendererPane.add(component);
        rendererPane.paintComponent(g, component, header, cellRect.x,
                cellRect.y, cellRect.width, cellRect.height, true);
    }

    public void setHeaderHeight(int iHeight) {
        m_height = iHeight;
    }
}

4、一个简单的测试用例 GroupableHeaderExample

import java.awt.Color;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.JTableHeader;

import org.f5.ui.table.ColumnGroup;
import org.f5.ui.table.GroupableTableHeader;

/**
 * @version 1.0 11/09/98
 */
public class GroupableHeaderExample extends JFrame {

    GroupableHeaderExample() {
        super("Groupable Header Example");

        initialize();
    }
    private void initialize() {
        DefaultTableModel dm = new DefaultTableModel();
        dm.setDataVector(new Object[][] {
                { "119", "foo", "bar", "ja", "ko", "zh" },
                { "911", "bar", "foo", "en", "fr", "pt" } }, new Object[] {
                "SNo.", "1", "2", "Native", "2", "3" });
        JTable table = new JTable(dm) {
            protected JTableHeader createDefaultTableHeader() {
                return new GroupableTableHeader(columnModel);
            }
        };
        GroupableTableHeader header = (GroupableTableHeader) table
                .getTableHeader();
        javax.swing.table.TableColumnModel cm = table.getColumnModel();
        // 接受类型
        ColumnGroup g_jslx = new ColumnGroup(
                "接收类型");
        g_jslx.add(cm.getColumn(1));
        g_jslx.add(cm.getColumn(2));
        header.addColumnGroup(g_jslx);
      
        JScrollPane scroll = new JScrollPane(table);
        getContentPane().add(scroll);
        setSize(400, 120);
        //设置列头背景为红色
        header.setBackground(Color.RED);
    }

    public static void main(String[] args) {
        GroupableHeaderExample frame = new GroupableHeaderExample();
        frame.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
        frame.setVisible(true);
    }
}

5、效果图
等我会贴图了再贴上来吧